The potential role of aberrant amygdala activity in the behavioral abnormalities of emotion processing in schizophrenia has been examined in two meta-analyses. One study observed under-recruitment of the amygdala regardless of whether the task was explicit or implicit, and independent of chronicity (Li et al., 2010). The other study replicated reduced amygdala activation, but importantly found that this deficit was only present when directly contrasting emotional to neutral expressions. This conclusion is consistent with previous reports of amygdala overactivation to neutral expressions (Gur et al., 2002; Hall et al., 2008). Further supporting the amygdala overactivation hypothesis, we found that while healthy participants activated amygdala and orbitofrontal cortex more when a neutral face was seen previously as threatening, patients activated these regions equally to both previously threatening and non-threatening faces (Satterthwaite et al., 2010).
